HANA backtrace 45/2011

Ok, it’s been more than the planned week since my last post in this series (HANA backtrace 44/2011) but these are very busy times lately for a primary support guy like I am.

I write this post from our US Headquarter offices in Newtown Square near Philadelphia and that’s because I’ve been asked to deliver several internal HANA training workshops for our AGS colleagues over here. Thus, I booked the flight, packed my bag and flew over here.
And there we are – right in the middle of a quite packed training week, covering topics like performance analysis, modelling, data services and backup/recovery (and lots more).
And just as we’re in full flight, we see HANA SPS 03 being released to customers.

With this, many new features, usage types and bug fixes have been made available to HANA users.
Make sure not to miss out on the updated SAP HANA documentation.

With SPS 03 a new software installation tool (Software Update Manager, SUM) had been released for HANA systems.
See SAP note #1545815 SAP Release Note for SUM for SAP HANA 1.0 to get the details.
The nice thing about this is, you can easily manage the upgrades of HANA related software parts all at once.

As far as I know, the pricing in HANA is based on the amount of data used with HANA, so the importance of a proper sizing is self-explanatory. SAP Note#1637145 SAP BW on HANA: Sizing SAP In-Memory Databasecontains the information about how to size a HANA system if you want to migrate your existing SAP BW system to it.

Which reminds me: BW on HANA has also been made available by the release of HANA SPS 03 and SAP BW SP5.

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Also related to the migration of ABAP systems to run on HANA is note#1634681 DB Migration: Report for finding large Row Store Tableswhich basically makes sure that you don’t overlook very large tables that should be put to the row store.
Why can this be an issue?
That’s because unlike column store tables, row store tables are always fully loaded into memory on HANA instance startup. So if too much data is put into such tables, it might be that the instance won’t come up anymore, since the automatic loading of these tables fails.

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As with all NetWeaver main databases, which is a use case for HANA as well (e.g. BW on HANA) there is the usage of a database sequence called DDLOG_SEQ. Unfortunately, older HANA revisions didn’t support persisted sequences, so after a restart of the HANA instance, the instance would actually be reset to its initial value.
To prevent this, see SAP note #1648526 Incorrect values for DDLOG sequence.

Talking about HANA usage with NetWeaver systems, the database interface library (DBSL) is a core piece of technology – so make sure to have SAP note #1600066 – verfügbare Patches der DBSL für NewDBon your radar to keep track of the latest fixes to it.

I was quite happy to learn that there are also helper tools for HANA created for mere support folks like me when I found SAP note #1647717 Für den SAP-Support: Prüfprogramm für Tabellen.
This note contains a little check program that looks out for tables stored in HANAs column store that might require a MERGE of the delta indexes (in case the automatic MERGE had been turned off).

Nicely also SAP note #1652078 SAP HANA database: Hardware checkis also kinda support related.
Since HANA revision 18, a little python script is delivered with HANA and executed during installation time.
It basically checks and reports whether your hardware is actually supported for HANA and it looks like my test instance definitively is not… 🙁

Other releases

As I barely had time to go through the notes while preparing my training sessions, I didn’t make it to the blogs on HANA this week. However, I’ve seen that there had been several HANA related posting, especially in connection to the recent SAP TechED, so give yourself a treat and check “SAP Blogs on In-Memory Business Data Management” to catch up with them

So, that’s it for this week. I expect more to come for HANA, so see you next week.